var DataView = require('./_DataView'),
    Map = require('./_Map'),
    Promise = require('./_Promise'),
    Set = require('./_Set'),
    WeakMap = require('./_WeakMap'),
    baseGetTag = require('./_baseGetTag'),
    toSource = require('./_toSource');

/** `Object#toString` result references. */
var mapTag = '[object Map]',
    objectTag = '[object Object]',
    promiseTag = '[object Promise]',
    setTag = '[object Set]',
    weakMapTag = '[object WeakMap]';

var dataViewTag = '[object DataView]';

/** Detect free variable `globalThis` */
const freeGlobalThis = typeof globalThis == 'object' && globalThis !== null && globalThis.Object == Object && globalThis;

/** Used to detect maps, sets, and weakmaps. */
var dataViewCtorString = toSource(DataView),
    mapCtorString = toSource(Map),
    promiseCtorString = toSource(Promise),
    setCtorString = toSource(Set),
    weakMapCtorString = toSource(WeakMap);

/**
 * Gets the `toStringTag` of `value`.
 *
 * @private
 * @param {*} value The value to query.
 * @returns {string} Returns the `toStringTag`.
 */
var getTag = baseGetTag;

// Fallback for data views, maps, sets, and weak maps in IE 11 and promises in Node.js < 6.
if ((DataView && getTag(new DataView(new ArrayBuffer(1))) != dataViewTag) ||
    (Map && getTag(new Map) != mapTag) ||
    (Promise && getTag(Promise.resolve()) != promiseTag) ||
    (Set && getTag(new Set) != setTag) ||
    (WeakMap && getTag(new WeakMap) != weakMapTag)) {
  getTag = function(value) {
    var result = baseGetTag(value),
        Ctor = result == objectTag ? value.constructor : undefined,
        ctorString = Ctor ? toSource(Ctor) : '';

    if (ctorString) {
      switch (ctorString) {
        case dataViewCtorString: return dataViewTag;
        case mapCtorString: return mapTag;
        case promiseCtorString: return promiseTag;
        case setCtorString: return setTag;
        case weakMapCtorString: return weakMapTag;
      }
    }
    return result;
  };
}

module.exports = getTag;